interoperability

[Juan Carlos Albores Aguilar]

is the following possible?? if so, could you explain me how or point me documentation about it??. I create end-user certificates and sign them by my own CA, this kind of PKI is working on a apache+openssl+modssl system and i would like to make this certificates to be accepted to other CA's, in somehow, to interoperate with other certificates or higher,  that my CA interoperates with other CA's. I understan that we're working with X.509 certificates so the "fields thing" cannot change but i'm talking about when other CA has the same structure for its certificates and i want to take its certificates as mine or viceversa, let's say, Verisign certificates, is it technically possible that its certificates and ours could interoperate?? or maybe with DoD certificates??.  Of course it has to be an agreement and all those, i repeate, technically.   Any comments or directions will help so please comment, thanks.   Juan Carlos Albores Aguilar